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Using the Struts validation framework

The Struts validation framework provides automatic validation of forms using configuration files. The validation.xml and validator-rules.xml are the two configuration files used by the Struts validation framework to validate forms.

Note: More information about the architecture and further documentation of Struts validation framework can be found at: http://struts.apache.org

To validate the logonForm using the Struts validation framework, do these steps:

We have provided a validation.xml and validation-rules.xml as part of the sample code in C:\7672code\struts\validation. Import the two files into RAD75StrutsWeb/WebContent/WEB-INF (you can also drag the files from Windows Explorer into the WEB-INF folder in Application Developer).

Add the Struts validator plug-in and required property to the plug-in indicating the location of the validation configuration files:

Expand RAD75StrutsWeb Æ WebContent Æ WEB-INF.

Open the struts-config.xml file in the Struts Configuration Editor.

Select the Plug-ins tab in the Struts Configuration Editor.

Click Add for Plug-ins, type ValidatorPlugIn, select the matching class from the struts-core-1.3.8.jar, and click OK. The Struts validator plug-in has now been added.

Add the required parameter by clicking Add under the Plug-in Mapping Extensions, and set the Property field to pathnames and the Value field to /WEB-INF/validator-rules.xml,/WEB-INF/validation.xml.

The Source tab shows:

<plug-in className="org.apache.struts.validator.ValidatorPlugIn">

<set-property property="pathnames"

value="/WEB-INF/validator-rules.xml,/WEB-INF/validation.xml"/>

</plug-in>

Save and close the Struts configuration file.

The validation.xml file contains the following elements:

All the Struts form beans

The fields within the form bean that is validated

The rule that is applied to validate the bean

The snippet that validates the logonForm and makes the ssn field required is shown in Example | 5-2.

Example 15-2 validation.xml snippet: LogonForm

<form-validation>

	<formset>

		<form name="logonForm">

			<field property="ssn" depends="required">

				<arg0 key="form.ssn" />

			</field>

		</form>

	</formset>

	.......

	.......

</form-validation>

The validator-rules.xml file contains the configuration for all the rules defined in the validation.xml file:

The snippet for the required rule is shown in Example | 5-3.

Example 15-3 validator-rules.xml snippet: Rule configuration for the required rule

<form-validation>

	<global>

		<validator name="required"

			classname="org.apache.struts.validator.FieldChecks"

			method="validateRequired"

			methodParams="java.lang.Object,

								org.apache.commons.validator.ValidatorAction,

								org.apache.commons.validator.Field,

								org.apache.struts.action.ActionErrors,

								javax.servlet.http.HttpServletRequest"

			msg="errors.required" />

	</global>

</form-validation>

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